With the increasing dissemination of research-based substance use prevention curricula, attention is now turning to promoting the fidelity of implementation. Fidelity refers to several components of implementation, including adhering to prescribed curriculum methods, insuring appropriate teaching methods, and making appropriate adaptations when needed that do not threaten the curriculum's integrity. To implement with fidelity, teachers need to understand the curriculum's objectives, and need to be motivated to deliver the program as designed. To promote fidelity, manuals and brief initial training have become standard procedure, and developers are now making use of information delivered through online and multimedia mechanisms, as well as technical assistance upon request. However, research on the dissemination of educational innovations suggests that personalized coaching may also be necessary to achieve prevention goals. The proposed study will test the relative effects of two training conditions to support the implementation of All Stars, a research-based curriculum. Teachers in the "standard" training condition will receive initial training, technical assistance on request, online and video instruction about the program, and Internet-based "just-in-time" support. In addition to the standard training components, teachers in the "enhanced" training condition will receive onsite coaching, proactive technical assistance, and will participate in a program to recognize their mastery of curriculum delivery. We will test the effects of training in a randomized experimental design, following teachers over three consecutive years. Their curriculum adherence, promotion of student interactivity, curriculum adaptations, motivation to implement the program, and understanding of targeted mediators will be assessed through videotaped observations of their classroom performance and through surveys and interviews. Effects on student-level mediators and substance use will be measured through student surveys. The cost-effectiveness of the enhanced relative to the standard training conditions will be assessed. Study results will inform the prevention field concerning the potential for personalized coaching and technical assistance to promote curriculum fidelity and affect key student-level mediating variables.